“So many times, you will see problems that cannot be fully addressed by the auto OEM’s specifications,” says José Puente Cabrero, SSAB Product Manager for Docol Cold-Rolled AHSS. “When you look at the entire production process, the AHSS specifications are maybe 20% of the challenges that a material actually needs to address.
“For example, we can be discussing the OEM’s requirement for elongation or bendability of a part and discover that what the OEM really is concerned about is how the part behaves during a crash test. Now that’s something that’s very difficult to express in a simple specification.
“Instead of just specifications, SSAB, as an AHSS supplier, really needs a comprehensive understanding of the part’s role. We need to understand how that part will interact with surrounding parts. How will it be joined? What crash tests are relevant? What are the loads of those crash tests? What are the relevant criteria in those tests?
“The ideal scenario is when the OEM, the parts manufacturer, and the AHSS/UHSS producer work together in the very early stage of the car design. In other words: What are the OEM’s ultimate goals for this part? If we know the OEM’s end goals, we can work backwards, so together we figure out the optimized geometries, the forming, and which AHSS steel to use.
“SSAB’s experience is that when we come across a very strict tolerance, we have to ask: ‘What is behind this requirement?’ Is the OEM attempting to address a production problem — like shape consistency — by raising supplier specifications?
“What works better for everyone — for the entire process and the end results — is when, at the very initial designing steps for a part, you’re also thinking about which material you’ll use, and how it’ll be formed, and how it will respond to those forming processes. When designers think like that, their design becomes more optimized — and so will the forming and the final part’s shape consistency.”